Zygomatic Bone-to-Implant Contact in 77 Patients With Partially or Completely Edentulous Maxillas

doi:10.1016/j.joms.2012.05.016

Journal of Oral and Maxillofacial Surgery

Volume 70, Issue 9, September 2012, Pages 2065-2069

https://doi.org/10.1016/j.joms.2012.05.016 Get rights and content

Purpose

Specifically with zygomatic implants, the bone-to-implant contact (BIC) at the zygomatic bone correlates with the survival of the implant because there is little anchorage at the alveolus. The purpose of this retrospective study was to view and measure the BIC of zygomatic implants in the zygomatic bone.

Materials and Methods

The patients in this study received zygomatic implants at a single private dental implant center. All patients were treated with the same immediate-loading protocol followed by postoperative cone beam computed tomography. The scans were exported to a computer-aided design system, where the BICs could be measured digitally. The BIC was analyzed by gender, and any statistical difference was determined by analysis of variance.

Results

The study sample was composed of 77 patients (62.3% women) receiving 173 zygomatic implants. The mean age of the sample was 59 ± 8.7 years. The mean BIC was 15.3 ± 5.6 mm (range, 4.9 to 32.9 mm) in the zygomatic bone. On average, 35.9% ± 11.7% (range, 12.2% to 67.3%) of the implant came into contact with the zygomatic bone. The average BIC in men was 16.5 ± 6.0 mm, and the average BIC in women was 14.7 ± 5.4 mm, a statistically significant difference by analysis of variance (P < .05).

Conclusions

Evidence from this report indicates the zygomatic BIC varies greatly from patient to patient. These data show that the typical male patient has a greater zygomatic BIC than the typical female patient; however, these data do not support the hypothesis that the zygomatic BIC influences the zygomatic implant survival rate.

Section snippets

Study Design/Sample

This retrospective study follows the guidelines for IRB exemption according to Ethical & Independent Review Services. To address the research purpose, the investigators designed and implemented a retrospective cohort study in which all patients who had zygomatic implants placed at a private clinical facility (PI Dental Center, Institute for Facial Esthetics, Fort Washington, PA) were analyzed. All patients were treated according to the Teeth in A Day protocol,30, 31 that is, all implants were

Results

Seventy-seven patients (31 men, 46 women; mean age, 59 ± 8.7 yr; age range, 33 to 80 yr) who underwent oral reconstruction because of severely atrophied maxillas were treated with 173 zygomatic implants (range, 1 to 4 implants). The overall implant survival rate was 96.5% (Table 1). Sixty-three of 66 implants (95.5%) placed in men survived, whereas 104 of 107 implants (97.2%) placed in women survived. The survival rates between men and women were statistically similar (P > .05). The 6 zygomatic

Discussion

The purpose of this retrospective study was to examine the BIC by measuring how much of the apical portion of the zygomatic implant was in contact with the zygoma. This appeared to be an important topic of study because with an increased understanding of the BIC comes an increased understanding of the factors related to osseointegration and successful immediate prosthetic loading. With an increase of zygomatic BIC, there is an overall inherent increase in prosthetic anchorage in patients with a

References (34)

S. Isaksson et al.
Maxillary alveolar ridge augmentation with onlay bone-grafts and immediate endosseous implants
J Craniomaxillofac Surg
(1992)
C.D. Briggs et al.
Systematic review of minimally invasive pancreatic resection
J Gastrointest Surg
(2009)
Y. Lotan et al.
The new economics of radical prostatectomy: Cost comparison of open, laparoscopic and robot assisted techniques
J Urol
(2004)
O.T. Jensen et al.
The maxillary M-4: A technical and biomechanical note for all-on-4 management of severe maxillary atrophy—Report of 3 cases
J Oral Maxillofac Surg
(2009)
T. Mattsson et al.
Implant treatment without bone grafting in severely resorbed edentulous maxillae
J Oral Maxillofac Surg
(1999)
K. Ujigawa et al.
Three-dimensional finite elemental analysis of zygomatic implants in craniofacial structures
Int J Oral Maxillofac Surg
(2007)
J.S. Sherry et al.
Treatment of a severely atrophic maxilla using an immediately loaded, implant-supported fixed prosthesis without the use of bone grafts: A clinical report
J Prosthet Dent
(2010)
B.A. Jung et al.
Bone-to-implant contact of orthodontic implants in humans—A histomorphometric investigation
Eur J Orthod
(2008)
R. Adell et al.
15-year study of osseointegrated implants in the treatment of the edentulous jaw
Int J Oral Surg
(1981)
L.R. Koser et al.
Length determination of zygomatic implants using tridimensional computed tomography
Braz J Oral Res
(2006)

R. Brånemark et al.

Osseointegration in skeletal reconstruction and rehabilitation: A review

J Rehabil Res Dev

(2001)

R.M. Wood et al.

Grafting of the maxillary sinus with intraorally harvested autogenous bone prior to implant placement

Int J Oral Maxillofac Implants

(1988)

K.W. Higuchi

Minimization of bone grafting in the orofacial region

D.E. Tolman

Reconstructive procedures with endosseous implants in grafted bone: A review of the literature

Int J Oral Maxillofac Implants

(1995)

P. Dasgupta et al.

Outcomes of robotic assisted radical prostatectomy

Int J Urol

(2009)

S.R. Schell et al.

Laparoscopic adrenalectomy for nonmalignant disease: Improved safety, morbidity, and cost-effectiveness

Surg Endosc

(1999)

L. Bencini et al.

Incisional hernia: Repair retrospective comparison of laparoscopic and open techniques

Surg Endosc

(2003)

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Zygomatic implant treatment is widely applied for severe maxillary atrophy to help rehabilitate the maxillary dentition. This retrospective study was performed to evaluate the actual radiographic bone–implant contact (rBIC) lengths of zygomatic implants. The records of 28 patients who underwent zygomatic implant surgery and subsequent follow-up examinations between August 2013 and September 2018 in the Department of Oral and Maxillofacial Surgery, Taipei Tzu Chi Hospital were reviewed. The surgeries were performed by a single surgeon using the same treatment protocol. All patients had a computed tomography scan at 1 year after the surgery. Using three-dimensional imaging software, an investigator measured the rBIC lengths of 66 implants and documented their clinical status. The implant survival rate was 100%. The mean rBIC length was significantly longer in male patients than in female patients (20.80 ± 5.88 mm versus 17.79 ± 6.34 mm; P = 0.028). The mean rBIC length of double zygomatic implants was significantly longer when compared to that of single implants (21.11 ± 6.23 mm versus 17.75 ± 5.85 mm; P = 0.027). This article is novel in reporting the exact rBIC lengths of zygomatic implants in a clinical setting. The results showed that zygomatic implants are a viable treatment modality for full-mouth rehabilitation.
Real-time navigation system in implant dentistry
2021, Computer-Aided Oral and Maxillofacial Surgery: Developments, Applications, and Future Perspectives
For patients treated with conventional dental implants, computer-assisted implant surgery includes a dynamic navigation system and digital surgical guide plate, both of which can achieve satisfactory accuracy. With the continuous improvement of medical devices, the application of the dynamic navigation system in the field of dental implant is widely increasing. The ideal implant position can be planned through the dynamic navigation system software, and the system can accurately transfer the preoperative design to the operation under operator guidance. This feature is especially important for aesthetic areas of anterior teeth and cases with complex anatomical conditions in the operation area. For patients who suffer from severe maxillary atrophy, this system has also been gradually used in zygomatic implant surgery and represents a reliable and promising approach for the rehabilitation of oral function. This chapter aims to describe the background of the real-time navigation system in both conventional implant and zygomatic implant surgery and briefly introduce the workflow along with the advantages and limitations of the system in clinical applications. Finally, future development of navigation systems will also be discussed.
A Novel Prosthetically Driven Workflow Using Zygomatic Implants: The Restoratively Aimed Zygomatic Implant Routine
2020, Journal of Oral and Maxillofacial Surgery
Zygomatic implants present a unique treatment option for patients with severe resorption of the maxilla; however, palatally positioned zygomatic implant platforms will result in a significant buccopalatal cantilever, speech disturbances, and unhygienic prosthesis contours. The purpose of the present study was to introduce a novel preoperative workflow to help attain predictable surgical and prosthetic outcomes with zygomatic implants.
To minimize prosthetic complications, an appropriate preoperative workup is imperative. A restoratively driven approach commonly used in traditional intra-alveolar implant dentistry has been adapted for zygomatic implant rehabilitation and described in the present report.
With zygomatic implants, applying a prosthetically driven approach is possible. However, it involves a unique application of traditional biomechanical and soft tissue principles of implant dentistry and digital integration of the prosthetic and surgical treatment plans.
Striving to attain zygomatic implant platforms as close as possible to the central fossae and cingulum of prosthetic teeth should be the goal when placing zygomatic implants. The restoratively aimed zygomatic implant routine introduced in the present report is a progressive and modern approach to prosthetically driven implant rehabilitation.
Virtual quad zygoma implant placement using cone beam computed tomography: sufficiency of malar bone volume, intraosseous implant length, and relationship to the sinus according to the degree of alveolar bone atrophy
2018, International Journal of Oral and Maxillofacial Surgery
Citation Excerpt :
In the present study, anterior or posterior positioning and the different classes of alveolar bone atrophy changed the angulation of the implant and confirmed this hypothesis with statistical evidence. Similarly, the present results regarding the intra-malar implant length are comparable to those published by Balshi et al.15, with a discrepancy of 1.65 mm. This small difference may be attributable to several factors, which include the fact that Balshi et al. performed measurements at the lowermost part of the implant in contact with the malar bone, while in the present study the longitudinal implant axis was used.
The objective of this study was to investigate the malar bone volume and length that a zygomatic implant can engage, and the relationship to the sinus according to the degree of alveolar bone atrophy. A three-dimensional evaluation was performed using cone beam computed tomography scans from 23 patients with a totally edentulous maxilla; quad zygoma implants were virtually placed. The predictor variable was the amount of malar bone volume and length that a zygomatic implant can engage. The primary outcome variable was the relationship to the sinus according to the degree of alveolar bone atrophy. Other variables were the residual alveolar bone height to the floor of the sinus and the nasal cavity. The mean volume of malar bone engaged in this sample of 92 zygomatic implants was 0.19 ± 0.06 cm³. The implant had an extrasinus path in 60.9% of cases, a parasinus path in 25%, and an intrasinus path in 14.1%. The results suggest that the average volume of malar bone engaged by a zygomatic implant is constant regardless of implant position and the degree of alveolar bone atrophy. As alveolar atrophy increases, the trajectory of the implant becomes more parasinus and intrasinus. The examiners were able to find enough bone to adequately distribute the implants in all cases.
Application of Real-Time Surgical Navigation for Zygomatic Implant Insertion in Patients With Severely Atrophic Maxilla
2018, Journal of Oral and Maxillofacial Surgery
Citation Excerpt :
The outcome of navigation surgery in this study was evaluated by the radiologic bone-to-implant contact (rBIC) area in the zygoma. The rBIC area was determined with postoperative CBCT and by measuring the apical portion of the ZI in contact with the zygomatic bone, as described in a previous study.17 The postoperative data were exported to iPlan software, and the BIC area in the zygoma was measured when a clear image of the implant in zygomatic bone was visible (Fig 7).
Computer-aided treatment technology has extended its applications to oral implantology. This report describes the authors' initial clinical experience on the application of a commercially available navigation system (VectorVision) in zygomatic implant (ZI) insertion in the severely atrophic maxilla.
This was a retrospective longitudinal study. Eligible patients with maxillary edentulism who were treated with ZI placement were enrolled. Treatment planning was performed on the computer based on previously obtained 3-dimensional imaging data. The surgical procedure was carried out under the guidance of a surgical navigation system. The outcome variable was safety and additional variables were ZI survival rate and radiologic bone-to-implant contact (rBIC) area in the zygoma. Statistical analysis was performed with SPSS 16.0 for Windows (SPSS, Inc, Chicago, IL).
Fifteen patients (8 men, 7 women; age range, 30 to 69 yr; average age, 43 ± 3.5 yr) were eligible for the study and were enrolled from May 2015 through September 2016. Of the included patients, each of 4 patients received 1 ZI on each side of the zygomatic bone and 2 to 4 standard implants in the edentulous anterior maxilla; the other 11 received a ZI “quad approach” without standard implant insertion. All ZIs were anchored in the site of the maxillary alveolar process and zygomatic bone, and no critical anatomic structure injuries occurred during insertion and postoperative radiographic examination. All ZIs achieved osseointegration, for an overall survival rate of 100% after early healing. The overall rBIC area of ZIs in the study was 4.1 to 24.7 mm (average, 14.5 ± 4.6 mm).
For the limited clinical cases treated in this study, the procedure for ZI placement was feasible and reliable with the guidance of the surgical navigation system. In addition, the potential risk of complications was minimized and ZIs were placed to make the best possible use of the available bone volume.
Survival and Complications of Zygomatic Implants: An Updated Systematic Review
2016, Journal of Oral and Maxillofacial Surgery
To assess the survival rate of zygomatic implants (ZIs) and the prevalence of complications based on previously published studies.
An electronic search of 3 databases was performed in December 2015 and was supplemented by manual searching. Clinical series of ZIs were included. Interval survival rate and cumulative survival rate (CSR) were calculated. The untransformed proportion of complications (sinusitis, soft tissue infection, paresthesia, oroantral fistulas) was calculated by considering the prevalence reported in the studies.
Sixty-eight studies were included, comprising 4,556 ZIs in 2,161 patients with 103 failures. The 12-year CSR was 95.21%. Most failures were detected within the 6-month postsurgical period. Studies (n = 26) that exclusively evaluated immediate loading showed a statistically lower ZI failure rate than studies (n = 34) evaluating delayed loading protocols (P = .003). Studies (n = 5) evaluating ZIs for the rehabilitation of patients after maxillary resections presented lower survival rates. The probability of presenting postoperative complications with ZIs was as follows: sinusitis, 2.4% (95% confidence interval [CI], 1.8-3.0); soft tissue infection, 2.0% (95% CI, 1.2-2.8); paresthesia, 1.0% (95% CI, 0.5-1.4); and oroantral fistulas, 0.4% (95% CI, 0.1-0.6). However, these numbers might be underestimated, because many studies failed to mention the prevalence of these complications.
ZIs present a high 12-year CSR, with most failures occurring at the early stages postoperatively. The main observed complication related to ZIs was sinusitis, which can appear several years after ZI installation surgery.

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Dental implantsZygomatic Bone-to-Implant Contact in 77 Patients With Partially or Completely Edentulous Maxillas

Purpose

Materials and Methods

Results

Conclusions

Section snippets

Study Design/Sample

Results

Discussion

J Craniomaxillofac Surg

J Gastrointest Surg

J Urol

J Oral Maxillofac Surg

J Oral Maxillofac Surg

Int J Oral Maxillofac Surg

J Prosthet Dent

Bone-to-implant contact of orthodontic implants in humans—A histomorphometric investigation

Eur J Orthod

15-year study of osseointegrated implants in the treatment of the edentulous jaw

Int J Oral Surg

Length determination of zygomatic implants using tridimensional computed tomography

Braz J Oral Res

Osseointegration in skeletal reconstruction and rehabilitation: A review

J Rehabil Res Dev

Grafting of the maxillary sinus with intraorally harvested autogenous bone prior to implant placement

Int J Oral Maxillofac Implants

Minimization of bone grafting in the orofacial region

Reconstructive procedures with endosseous implants in grafted bone: A review of the literature

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Outcomes of robotic assisted radical prostatectomy

Int J Urol

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Surg Endosc

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Dental implants
Zygomatic Bone-to-Implant Contact in 77 Patients With Partially or Completely Edentulous Maxillas